FIG. 9 shows an automotive door trim 1 which is given as an example of automotive interior components such as door trims, rear corner trims and so on, and this automotive door trim 1 consists of a resin core member 2 having a desired contour, and a surface skin member 3 which is integrally laminated on the surface of the resin core member 2.
The resin core member 2 is required to have highly complicated shapes to meet recent design requirements, and is typically fabricated by the mold press forming process or by molding resin material in semi-molten state in a mold press die set. To simplify the fabrication process, the surface skin member 3 is assembled to the resin core member 2 when molding the resin core member 2.
Referring to FIG. 10, with upper and lower dies 4 and 5 of a mold press die set opened up, the surface skin member 3 is placed between the upper and lower dies 4 and 5 by retaining the peripheral part of the surface skin member 3 with a clamping device 6. Thereafter, the upper die 5 is lowered until a prescribed gap is defined between the upper and lower dies 4 and 5, and resin material 8 consisting of polyolefin or other resin material in semi-molten state is distributed over the die surface of the lower die 4 from gates 7 provided in the lower die 4 so that the resin material 8 may be formed into the resin core member 2 having a desired curved contour and the surface skin member 3 may be integrally attached to the surface of the resin core member 2 at the same time.
However, according to this conventional process of combining a resin core member 2 and a surface skin member 3 simultaneous as mold press forming the resin core member 2, when the resin core member 2 has a complicated three-dimensional shape, air and reaction gas generating from the resin material 8 tends to remain in dips and bends of the die surface, and eventually collect in one place. This is known to cause creases in the surface skin member 3 when the upper and lower dies 4 and 5 are closed together as illustrated in FIG. 11. The air and the reaction gas may also cause voids in the resin core member 2.
This problem is even more pronounced in recent years as the upper and lower dies are fabricated with increasingly smaller tolerances as an effort to avoid the generation of burrs caused by resin material seeping through the parting line along the peripheral part of the upper and lower dies. It has been attempted to form a number of pin holes in the surface skin member 3 to remove trapped gas and air. However, in places where the surface skin member is stretched during the molding process, the resin material tends to seep out from the pin holes, and the surface skin member 3 gets damaged as a result.